1. The Field of the Invention
The present invention generally relates to electronic devices such as computers. More specifically, the present invention relates to communications cards that allow electronic devices and communications systems to be interconnected.
2. Description of Related Art
Portable computers and other electronic equipment frequently use communications cards to allow electrical communication to be established between electronic devices or to allow electronic devices to be connected to communication systems. The communications cards are typically located internally within the computer or electronic equipment and the cards are relatively small in size. These communications cards, for example, are commonly used with modems, fax/modems, Local Area Network (LAN) adaptors and cellular telephone equipment.
Conventional communications cards are often constructed according to the Personal Computer Memory Card International Association (PCMCIA) guidelines, which set forth the physical specifications and electronic architecture of the cards (also known as PC cards), and the ports or sockets into which the cards are inserted. The PCMCIA guidelines define three types of cards and sockets for support of electronic equipment. For instance, PCMCIA standards require all PC cards to have the same length and width (roughly the size of a credit card), and each card includes a connector to allow it to be connected to the host device. In particular, according to the known PCMCIA standards, PC cards have a length of 85.6 mm (3.4 inches), a width of 54.0 mm (2.1 inches), and a height of 3.3 mm (0.1 inches), 5.0 mm (0.2 inches) or 10.5 mm (0.4 inches) depending upon if the card is a Type I card, Type II card or Type III card, respectively. Type I PC cards are typically used for memory devices such as read only memory (RAM), flash memory or static random access memory (SRAM). Type II PC cards are generally used with input/output (I/O) devices such as data/fax modems, LANS and mass storage devices. Type III PC cards are used for devices whose components are thicker and require additional space. The PCMCIA guidelines also define corresponding types of sockets. Type I sockets support only Type I cards, Type II sockets support Type I and II cards, and Type III sockets supports all three types of cards.
A conventional PC card has a generally rectangular shaped body with a top surface, bottom surface, opposing sidewalls, front end and a rear end. The terms "front" and "rear" are used in reference to the direction in which the PC card is inserted into the receiving socket in the electronic device. A substrate such as a printed circuit board is disposed within the PC card and the substrate includes various electronic components that provide the necessary circuitry to perform the intended functions of the PC card. The front end of the PC card includes a 68-pin connector that is used to connect the card to the electronic device, such as a notebook or lap top computer.
In greater detail, when a conventional PC card is inserted into the socket in the electronic device, the 68-pin connector is connected to a corresponding receptacle or receiving portion. The receiving portion is typically a multiple pin connector that allows electrical communication to be established between the PC card and the electronic device. The receiving pin connector is typically sized and configured to closely receive the 68-pin connector and create an interference or friction engagement between the 68-pin connector and the receiving pin connector. This friction or interference fit helps hold the PC card within the socket and prevent the unintentional removal of the PC card from the socket.
The top surface of the 68-pin connector is freely exposed to allow the connector to be inserted into the receiving pin connector. Specifically, the top cover does not extend over the upper surface of the 68-pin connector because of the tight tolerances and close fit of the 68-pin connector within the receiving pin connector. Disadvantageously, because the top surface of the 68-pin connector is exposed, it can be easily damaged, scratched, dented and otherwise abused. Significantly, if the 68-pin connector is broken or severely damaged, it typically cannot be repaired and the entire PC card must be replaced. Additionally, the 68-pin connector does not provide any shielding or protection from electromagnetic radiation. Thus, the connector may cause electromagnetic interference (EMI), for example, with the host electronic device, the PC card itself, or other nearby electronic equipment.
In addition, conventional PC cards often have a gap between the body of the card and the connector because the top cover of the card does not extend over the upper surface of the 68-pin connector. Disadvantageously, this gap allows dirt, foreign objects and other materials to get inside the body of the card, and these foreign objects may damage the sensitive electronic components located inside the card. In severe instances, the foreign objects may short circuit the card or otherwise cause the card to fail. Additionally, the gap creates a potential electrical hazard because if electrically conducting material is inserted into the gap and it contacts components or wires with the card, this may create an electric shock danger.